Wireless input devices such as the wireless mouse have become popular because they eliminate the inconvenience associated with wires and cables. Among their shortcomings is that a wireless mouse is heavy compared to a conventional wired mouse because it requires batteries to power up. Although initially the extra weight may not be bothersome, frequent users will feel the additional stress and strain on their hand and wrist. This can lead to, or aggravate, stress-related injuries such as carpal tunnel syndrome.
Referring to FIG. 1a, there is shown a conventional computer system 100 using a wired mouse 102. The mouse derives its name from the resemblance to the animal of the same name. The wire is said to resemble the tail. Computer mice such as mouse 102 can detect the X-Y translation of the mouse position by mechanical or optical methods. The mouse movement is typically translated by a device driver (software that processes input from a device such as a mouse) to a relative movement of the cursor on the computer screen. As the mouse 102 is moved around a surface such as pad 104, the screen cursor moves as well in a well known relationship.
Computer system 100 includes a processing system which communicates with the input/output (I/O) devices. Examples of conventional I/O devices include a keyboard, mouse, display, removable and fixed recordable media (e.g., floppy disk drives, tape drives, CD-ROM drives, DVD-RW drives, Flash drives, etc.), touch screen displays and the like.
FIG. 1b illustrates the computer system of FIG. 1a with a typical wireless mouse 103. The wireless mouse 103 includes an optical system to detect X-Y translation of the mouse position. Mouse 103 also includes a radio transmitter to send wireless signals to the computer when the mouse position has changed. These signals cause the computer to update the location of a cursor displayed on a screen. Both the optical system and the radio transmitter are operated by batteries in the mouse 202. This mouse operates only on the pad 104, or on other surfaces that provide enough contrast so that the optical system can detect a change when the mouse is translated. If the mouse is lifted above the surface or placed on a highly reflective surface the optical system typically fails to detect movement in the X-Y plane correctly. The optical mouse 103 does not provide information on Z-translation (height) because conventional computer mice movement is limited to the x-y plane (e.g. movement over a mouse pad or a table).
US Published Application 2005/0219208 by Eichenberger et al. discloses a wireless input device, wherein a key stored in a receiver or a memory within the mouse can be transmitted by a radio-frequency identification (RFID) device provided in the mouse. This way, the mouse may be carried in a user's pocket and may be used to authenticate the user. However, the device disclosed uses conventional location determining means.
US Published Application 2005/0237295 by Anderson discloses a computer and RFID-based input device, wherein the input device can also operate together with another RFID product. For example, the computing arrangement can be adapted to receive and decode the signal from the RF transponders only when the computing arrangement detects the presence of an authorized RFID tag, which may be provided on a user ID card. However this device does not provide a radio frequency indication of the location of the mouse.
US Published Application 2006/0107061 by Holovacs discloses providing secure access to a KVM (keyboard, video, mouse) switch and other server management systems, wherein an RFID transceiver is coupled to or integrated with the system for detecting the presence of RFID tags that are within range of communications. A user workstation is only operable if the RFID transceiver detects a valid RFID tag.
US Published Application 2007/0195058 by Lin discloses a wireless cursor pointing device, which relates to a wireless cursor pointing device without the need for a battery. The wireless cursor pointing device transmits a signal through a Radio Frequency Identification (RFID) system. This device does not use RFID capability for location determining.
U.S. Pat. No. 7,027,039 issued to Henty discloses a computer system with a passive wireless mouse, wherein the passive mouse includes passive transponder tags configured adjacent to the perimeter of the mouse ball comprising a body portion of the mouse. Further, an oriented antenna design, inductive coupling pattern or capacitor pattern are provided in tags chosen so that the tuning and activation of one tag is provided by the vertical motion of the mouse ball whereas the other tag will be affected by the horizontal ball motion. Therefore, as the mouse ball is rotated the two tags will be tuned and detuned repeatedly with a duty cycle which corresponds to the velocity of the rotating mouse ball. This thus provides two components of the rotational motion of the mouse ball which can be used to provide the specific speed and direction of the mouse ball. This in turn can be used to accurately track mouse ball position to provide conventional mouse control functions. However this system lacks the capability to detect movement in three dimensions.
U.S. Pat. No. 7,280,097 to Chen et al. discloses a human interface input acceleration system, wherein in one implementation, the auxiliary input accelerator device may be a programmable radio frequency identification (RFID) key fob. Today, many workers gain access to their secure workplace via an RFID key fob. The circuitry in such a key fob may be housed inside an input accelerator with buttons, sensor arrays and a wireless communication protocol to be used as an auxiliary input accelerator device to the host device.
Therefore, there is a need for a pointing device that overcomes the shortcomings of the existing art. More specifically, none of the devices mentioned above uses the radio frequency (RF) signal to detect translation of the device or to acquire the device position.